Pressure

[horselady]

We have a Worcester boiler and the pressure seems to have dropped quite low, it's on the very bottom of the green, not quite on the red area. It certainly wasn't that low before. Can't find much info. except a bit that says if it permanently drops, the unit has to be re-pressurised. It was only serviced 2 months ago. Should I be concerned? I keep going to check on it and I'm getting on my own nerves 'cos I can't leave it alone! I'm sitting here in work imagining the house blowing up!!

[ummmm]

I don't think it will blow up...

There should be a valve that you turn that will raise the pressure. I don't know where it is on a bosch though. Our old one waqs underneath and you needed a screw driver to turn it.

[horselady]

Thank you, I didn't have a clue how to put this right but your info prompted me to google this and I found a step by step guide. As you say, there is a key and a valve underneath and we put it right last night. The guide also mentioned that when the radiators are bled the pressure can become too low, which is exactly what I did on Sunday, so that also explained why it dropped so suddenly!

[buildersmate]

Bleeding radiators takes volume (in this case air) out of the system, so this will always reduce the pressure on the dial compared to what you saw before if the system is 'closed' as yours is.
It sounds like you found the way to refill a Worcester-Bosch - the plastic 'key' thingy bridges a gap between the cold water infeed supply and a one-way valve on the sealed system side.
With the key put in, you can open the water supply valve when water flows through the key thingy.
You will get a few dribbles of water when you remove the key.